A new reactive force field to describe proton diffusion within the solid-oxide fuel cell material BaZrO3 has been derived. Using a quantum mechanical potential energy surface, the parameters of an interatomic potential model to describe hydroxyl groups within both pure and yttrium-doped BaZrO3 have been determined. Reactivity is then incorporated through the use of the empirical valence bond model. Molecular dynamics simulations (EVB-MD) have been performed to explore the diffusion of hydrogen using a stochastic thermostat and barostat whose equations are extended to the isostress-isothermal ensemble. In the low concentration limit, the presence of yttrium is found not to significantly influence the diffusivity of hydrogen, despite the proton having a longer residence time at oxygen adjacent to the dopant. This lack of influence is due to the fact that trapping occurs infrequently, even when the proton diffuses through octahedra adjacent to the dopant. The activation energy for diffusion is found to be 0.42 eV, in good agreement with experimental values, though the prefactor is slightly underestimated.
The relationship between activated H2 bond length and adsorption distance on MXenes identified with graph neural network and resonating valence bond theory
Quantum valence bond ice theory for proton-driven quantum spin-dipole liquids
基于最近在$κ$中发现的具有质子涨落的量子自旋液体的实验结果，结合量子质子冰和Anderson的共振价键自旋液体理论，提出了氢键电子系统中的混合量子液体$_3$（QSDL）理论。H-Cat）。在我们的理论中，电子自旋液体和质子偶极液体同时实现在基态称为$\textit{quantum valence bond ice}$。在这种状态下，两者都不能独立于另一个而建立。分析和数值计算表明，该态在自旋和偶极子之间有很大的纠缠熵，远远超过了（粗糙的）Born-Oppenheimer近似。我们还研究了QSDL的稳定性扰动和讨论的影响，实验中的H-猫和它的氘代模拟D-猫。
Possible valence-bond condensation in the frustrated cluster magnet LiZn2Mo3O8
从简单的成分中出现复杂的电子行为导致了许多物质状态的发现。在表现出几何磁阻挫的系统中发现了许多例子，这阻止了所有磁相互作用的同时满足。这种挫折产生了复杂的磁性，如手性自旋结构轨道驱动的磁性，自旋冰行为表现出狄拉克弦与磁单极，价键固体和自旋液体。在这里，我们报告的合成和表征LiZn 2 Mo 3 O 8，几何阻挫反铁磁体中的磁矩是本地化的小过渡金属簇，而不是个别离子。通过这样做，一阶Jahn-Teller不稳定性和轨道排序被阻止，允许在LiZn 2 Mo 3 O 8中的强相互作用的磁性团簇可能引起一个奇特的凝聚价键基态，让人想起所提出的共振价键态。我们的研究结果还将集群上的磁性与扩展固体中的几何磁性挫折联系起来，展示了一种新的方法，可以在寻找集体，紧急电子状态的物质时实现无与伦比的化学控制和可调性。
Valence Bond Order and Antiferromagnetism in Silicene - ab initio Results
硅烯和石墨烯相似，具有$π$ - $π^*$带。然而，硅烯的带宽仅为石墨烯的三分之一。这导致Hubbard U与带宽W的比率显著增加，石墨烯中的U/W $\sim$ 0.5比硅烯中的$\sim 1$。这种增强、二维性和唯象性表明硅烯（G. Baskaran，arXiv：1309.2242）.我们通过从头计算表明，与石墨烯不同，硅烯具有两种不稳定性：i）价键（凯库勒）二聚化和ii）弱的两个亚晶格反铁磁顺序，从而支持上述提议。这些不稳定性的存在，在费米面嵌套的情况下，指向莫特本地化，\textit{within the frame work of ab-initio scheme}。基底依赖的结构重建实验中看到的硅烯被解释为广义凯库勒键序。
